Added virtual machine descriptions and vagrant VM selection parameters to development environment setup documentation.  Removed —env=std option from OpenCV Homebrew (OS X) command line as it was not necessary and, with current versions, breaks the installation.

Modified lumify-twitter Markdown so URLs point to the public facing /altamiracorp/lumify and /altamiracorp/lumify-twitter project base URLs instead of the private /nearinfinity/lumify-enterprise.
add accumulo dependency